1. Field of the Invention
The present invention relates to a hydraulic brake pressure generation apparatus for a vehicle capable of increasing a depressing force applied to a brake pedal while the vehicle brakes.
2. Description of the Related Art
Generally, a conventional hydraulic brake pressure control apparatus is provided with two pistons for controlling fluid pressure of a brake apparatus having two brake systems. The apparatus is also provided with two fluid pressure chambers and wheel cylinders fluid pressure in which is controlled by the two pistons, and the fluid pressure chambers and the wheel cylinders are connected therewith by a fluid passage. The pistons are engaged with the brake pedal through a vacuum booster which is a force increasing apparatus utilizing negative pressure of the vehicle engine.
In the apparatus described above, when the brake pedal is depressed down, the vacuum booster generates a force which is several times as strong as that applied to the brake pedal, and the force of the vacuum booster is applied to the pistons thereby supplying the fluid pressure in the fluid pressure chamber of a master cylinder to the wheel cylinders, so that the braking force is applied to the vehicle wheels.
However, the vacuum booster is large in size which occupies largely a small limited space of the engine room. On the other hand, it is known to provide another apparatus utilizing fluid pressure for braking the vehicle wheels. However, a responsibility of the operation is not so good at an initial time of the operation due to a sliding resistance of the pistons.